While the improved treatment of human immunodeficiency virus type 1 (HIV-1) infection is available, the development of an effective and safe prophylactic vaccine against HIV-1 is still an unrealized goal. Encouragingly, the discovery of broadly neutralizing antibodies (bNAbs) from HIV-1 positive patients that are capable of neutralizing a broad spectrum of HIV-1 isolates of various clades has accelerated the progress of vaccine development in the past few years. Some of these bNAbs recognize the N-glycans on the viral surface gp120 glycoprotein. We have been interested in using the glycan epitopes recognized by bNAbs for the development of vaccines to elicit bNAb-like antibodies with broadly neutralizing activities. Toward this goal, we have identified novel hybrid-type structures with subnanomolar avidity toward several bNAbs including PG16, PGT121, PGT128-3C, 2G12, VRC13, VRC-PG05, VRC26.25, VRC26.09, PGDM1400, 35O22, and 10-1074. Here, we report the immunogenicity evaluation of a novel hybrid glycan conjugated to carrier DT_CRM197, a nontoxic mutant of the diphtheria toxin, for immunization in mice. Our results indicated that the IgG response was mainly against the chitobiose motif with nonspecific binding to a panel of N-glycans with reducing end GlcNAc–GlcNAc (chitobiose) printed on the glass slides. However, the IgM response was mainly toward the reducing end GlcNAc moiety. We further used the glycoconjugates of Man₃GlcNAc₂, Man₅GlcNAc₂, and Man₉GlcNAc₂ glycans for immunization, and a similar specificity pattern was observed. These findings suggest that the immunogenicity of chitobiose may interfere with the outcome of N-glycan-based vaccines, and modification may be necessary to increase the immunogenicity of the entire N-glycan epitope.

中文翻译：

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HIV广泛中和抗体识别的N-聚糖的免疫原性评价

虽然人类免疫缺陷病毒 1 型 (HIV-1) 感染的改进治疗是可行的，但开发一种有效且安全的 HIV-1 预防性疫苗仍然是一个未实现的目标。令人鼓舞的是，来自 HIV-1 阳性患者的广泛中和抗体 (bNAb) 的发现能够中和各种进化枝的广谱 HIV-1 分离物，这加速了过去几年疫苗开发的进展。其中一些 bNAb 识别病毒表面 gp120 糖蛋白上的 N-聚糖。我们一直有兴趣使用 bNAb 识别的聚糖表位来开发疫苗，以引发具有广泛中和活性的 bNAb 样抗体。朝着这个目标，我们已经确定了对包括 PG16 在内的几种 bNAb 具有亚纳摩尔亲和力的新型混合型结构，PGT121、PGT128-3C、2G12、VRC13、VRC-PG05、VRC26.25、VRC26.09、PGDM1400、35O22 和 10-1074。在这里，我们报告了与载体 DT 偶联的新型杂合聚糖的免疫原性评估_CRM197，一种白喉毒素的无毒突变体，用于小鼠免疫。我们的结果表明，IgG 反应主要针对壳二糖基序，该基序与一组 N-聚糖非特异性结合，其中还原端 GlcNAc-GlcNAc（壳二糖）印在载玻片上。然而，IgM 反应主要针对还原端 GlcNAc 部分。我们进一步使用了 Man ₃ GlcNAc ₂、 Man ₅ GlcNAc ₂和 Man ₉ GlcNAc _{2的糖缀合物}聚糖用于免疫，并观察到类似的特异性模式。这些发现表明，壳二糖的免疫原性可能会干扰基于 N-聚糖的疫苗的结果，并且可能需要进行修饰以增加整个 N-聚糖表位的免疫原性。